1. Field of the Invention
This invention relates to a fuel injection system for engines, and more particularly to a fuel injection system for internal combustion engines in which fuel is supplied to a plurality of cylinders by a single fuel injection valve.
2. Description of the Prior Art
It has been known in the art in the field of fuel injection type engines to supply fuel to a plurality of cylinders by a single injection valve located upstream of a branch-off part of intake passages the downstream ends of which are connected to the plurality of cylinders separately. Such a single point injection type engine is disclosed in Japanese Unexamined Patent Publication No. 55(1980)-12262.
This type of fuel injection system has the following drawbacks due to the branched off intake passages and the change-over of the fuel supply thereto. When the fuel is injected into the plurality of cylinders sequentially in synchronization with the rotation of the engines to conduct injection at the timing of intake stroke, the amount of the fuel actually injected into the cylinders changes according to the length of the intake passages and the intake inertia. Consequently, the air fuel ratio changes according to the position of the cylinders, which badly influences the emission performance.